1. Field of the Invention
The present invention relates to a medical bag and a method of manufacturing the same and, more particularly, to a soft plastic medical bag with improved blood platelet storage characteristics and improved blocking preventive characteristics, and a method of manufacturing the same.
2. Description of the Prior Art
Medical bags such as blood bags are recently made of soft plastic materials such as soft polyvinyl chloride or polyolefin-type resins. Plastic bags of this type are usually sterilized for medical safety. The sterilization of medical bags can be performed by several methods, and steam autoclaving is utilized to sterilize medical bags which contain a liquid. However, the plastic materials described above exhibit a blocking tendency at high temperatures during steam autoclaving; that is, the inner surfaces of the bag adhere to each other. Such a blocking tendency is also observed at room temperature, and the inner surfaces of the bag often adhere to each other during storage of the bag.
Further, when a blood bag is made of polyvinyl chloride, the blood platelets of the blood stored in the bag adhere to the inner surfaces of the bag, causing a poor storage performance. In order to solve this problem, it has been proposed to add to the polyvinyl chloride material a substance which imparts an anti-coagulating action to the blood platelets, and to transfer the substance onto the surface of the obtained bag. However, a satisfactory result has not been obtained.